This invention relates to the coating of a surface, and in particular, to the depositing of a thin film of material onto a surface.
As is known, coatings are often applied to metallic, woods or plastic surfaces whenever there is a need for an improvement in the performance, function and/or aesthetic characteristics of the surface itself. For example, a coating such as a house paint may be placed on an external surface of a home in order to protect the external surface of the home from environmental exposure. Further, when reduced surface friction and wear resistance is required, materials such as polytetra Flouroethylene may be deposited on a surface of an article. For example, it is common for the food engaging surface of a frying pan to be coated with a polytetra Flouroethylene layer in order to prevent the food from sticking during cooking.
Heretofore, substances have been bonded or attached to surfaces in a plurality of procedures including painting, plating anodizing, and the like. Although the materials, equipment and bonding mechanisms differ depending on the coating process, all follow similar procedures. First, the surface is prepared in some manner for the coating. Thereafter, the material is deposited on the surface. After a predetermined time period for drying and/or curing of the deposited coating, touching up the coating is often required. Finally, the equipment must be cleaned and the waste materials must be disposed. As described, the various processes for applying the coating to a surface are time consuming and, quite possibly expensive.
The selection of a coating process and of the materials to be used is determined utilizing a cost benefit analysis associated with the above-described steps. Consequently, a coating process is not only measured by performance, but also by the costs associated therewith and the environmental impact of the process. The use and disposal of acids or volatile or organic compounds, common and essential in most coating processes, pose a significant problem in the manufacturing community.
Therefore it is a primary object and feature of the present invention to provide a method and device for depositing a layer of material on a surface.
It is a further object and feature of the present invention to provide a device for depositing a layer of material on a surface which is simple and inexpensive to manufacture.
It is a further object and feature of the present invention to provide a device for depositing a layer of material on the surface which is inexpensive to operate and is recyclable.
It is a further object and feature of the present invention to provide a method of depositing a layer of material on the surface wherein the method requires no surface preparation.
It is a further object and feature of the present invention to provide a method for depositing a layer of material on the surface which requires no drying or curing for the material deposited thereon.
In accordance with the present invention, a device and method for depositing a layer of material on the surface is provided. The device includes a hub rotatable about an axis. A plurality of fibers project from the hub. The fibers are constructed from the material to be deposited on the surface. Means are provided for rotating the hub at a predetermined angular velocity such that a portion of the fibers engage the surface and melt. The melted material bonds to the surface without any preparation to the surface or the use of toxic materials.
It is contemplated that the device further includes a means for transporting the surface in a first direction along an axis perpendicular to the axis of rotation of the hub. It is further contemplated that the device including means for transporting the hub in a second, opposite direction along a second axis, generally parallel to the surface. Means are provided for varying the axial distance between the hub and the surface such that a generally constant length of each fiber will continually engage the surface.
The hub is generally cylindrical in shape and defines an outer peripheral surface. Each fiber projects from the outer peripheral surface of the hub and, may be integrally formed with the hub. In the preferred embodiment, the fiber is selected from the group of materials consisting of plastic compounds, metallics and ceramics.
In order to insure uniform melting, each fiber has a predetermined length and a predetermined diameter. It is contemplated that the length of each fiber will be generally equal, and the diameter of each fiber will be generally equal.
The method of the present invention includes providing a hub having a fiber constructed from the material to be deposited on the surface and moving the fiber across the surface such that a portion of the fiber engages the surface and melts thereon.
In a first embodiment, the step of moving the fiber across the surface includes the additional step of rotating the hub about a predetermined axis of rotation at a predetermined angular velocity. It is also contemplated to transport the hub along the axis parallel to the surface upon which the layer of material is to be deposited. As the fiber engages the surface and melts thereon, the axial distance between the hub and the surface is varied such that a generally constant length of the fiber engages the surface.
In an alternate embodiment, the method for depositing the layer of material on the surface includes interconnecting a fiber formed from the material to be deposited, onto a rotatable hub. The hub is spaced a predetermined distance from the surface. Thereafter, the hub is rotated about an axis of rotation such that a predetermined portion of fiber engages the surface and melts thereon.
It is contemplated that the method includes the further step of transporting the surface along the longitudinal axis perpendicular to the axis of rotation and varying the axial distance between the hub and the surface such that a constant length of fiber engages the surface. In the alternative, it is contemplated that the portion of the fiber engaging the surface may also be regulated by means of an external force acting on the spindle and transmitted to the fiber. It is further contemplated to transport the hub in a second, opposite direction to the movement of the surface along an axis parallel to the surface.